On Start the Week Stephanie Flanders discusses social mobility. Zadie Smith's novel NW is a portrait of modern urban life in which characters try, but mostly fail, to escape their past. The Conservative Minister David Willetts and the columnist Owen Jones discuss what meritocracy and opportunity mean in today's society. And the social historian David Kynaston looks to the end of the 1950s when meritocracy became the buzz word of the day.